final public class hello_world{
    public static void main(String[] args){
        hello hl=new hello();
        world wr=new world();
        System.out.println(hl.getString()+" "+wr.getString()+hl.JiaHao());
    }
}

class hello extends Sign{
	public static void main(String[] args){
	}

	String getString(){
		return "hello";
	}
}

class world{
	public static void main(String[] args){
	}

	String getString(){
		return "world";
	}
}

class Sign{
	String JiaHao(){
		return "+"; 
	}
}